<html>
    <head>
        <style>
            *{
                padding:0;
                margin:0;
            }
            .box-left{
                float:left;
                width:300px;
                background:#DE5E60;
                height:90%;
            }
            .box-right{
                /* margin-left:300px; */
                /* 触发BFC,而BFC不会重叠浮动元素 */
                overflow:hidden;
                /* 设置zoom:1来兼容IE6-浏览器 */
                zoom: 1;
                background:#222;
                height:100%;
            }
        </style>
    </head>
    <body>
        <div class="box-left">

        </div>
        <div class="box-right">

        </div>
    </body>
</html>